乙酰胆碱对培养T细胞功能的作用

本文研究不同浓度（１０＾－１０－１０＾－４ｍｏｌ／Ｌ）乙酰胆碱（ＡＣｈ）对离体培养的大鼠脾脏Ｔ淋巴细胞增殖的影响,并探讨其作用机制。实验结果表明：１０＾－９－１０＾－４ｍｏｌ／Ｌ可显著增强Ｔ细胞由刀豆素Ａ（Ｃ－Ａ）诱导的增殖反应,以１０＾－７－１０＾－６ｍｏｌ／Ｌ时最强。淋巴细胞先用ＡＣｈ刺激１ｈ或者刺激１ｈ后洗弃ＡＣｈ,再用ＣｏｎＡ诱导６ｈ的Ｔ细胞的增殖。１０＾－７－１０－６ｍｏｌ／Ｌ阿托品可阻     

Therapeutic gene modified cell based cancer vaccines

History of cancer immunotherapy lasts for more than 120 years. In 1891 William B. Coley injected bacteria into inoperable cancer (bone sarcoma) and observed tumor shrinkage. He is recognized as the "'"Father of Immunotherapy"'". Cancer immunotherapy is based on the ability of the immune system to recognize cancer cells and to affect their growth and expansion. Beside the fact that, tumor cells are genetically distinct from their normal counterparts, and should be recognized and eliminated by immune system, the tumor associated antigens (TAAs) are often poorly immunogenic due to immunoediting. This process allows tumor to evolve during continuous interactions with the host immune system, and eventually escape from immune surveillance. Furthermore, tumor microenvironment consists of immunosuppressive cells that release immunosuppressive factors including IL-6, IL-10, IDO, TGFβ or VEGF. Interactions between cancer and stroma cells create network of immunosuppressive pathways, while activation of immune defense is inhibited. A key to successful immunotherapy is to overcome the local immunosuppression within tumor microenvironment and activate mechanisms that lead to tumor eradication. There are two clinical approaches of immunotherapy: active and passive. Active immunotherapy involves stimulation of immune response to tumor associated antigens (TAAs), either non-specifically via immunomodulating agents or specifically employing cancer vaccines. This review presents the progress and breakthroughs in design, development and clinical application of selected cell-based tumor vaccines achieved due to the generation and development of gene transfer technologies.     

三维适形调强放疗联合榄香烯注射液对食管癌患者血清肿瘤标志物和T淋巴细胞亚群的影响

摘要 目的：探讨三维适形调强放疗联合榄香烯注射液对食管癌患者血清肿瘤标志物和T淋巴细胞亚群的影响。方法：选取我院于2016年8月到2019年12月期间接诊的食管癌患者60例,根据随机数字表法分为对照组（n=30）和研究组（n=30）,对照组患者予以三维适形调强放疗,研究组在对照组基础上联合榄香烯注射液治疗,比较两组患者疗效、生存质量、血清肿瘤标志物、T淋巴细胞亚群以及不良反应。结果：研究组患者治疗6周后的临床总有效率为63.33%（19/30）,高于对照组患者的36.67%（11/30）（P<0.05）。两组治疗6周后血清癌胚抗原（CEA）、糖类抗原199（CA199）水平均较治疗前降低,且研究组低于对照组（P<0.05）。两组患者治疗6周后CD3⁺、CD4⁺、CD4⁺/CD8⁺水平均下降,但研究组高于对照组（P<0.05）,CD8⁺水平均升高,但研究组低于对照组（P<0.05）。两组治疗6周后卡劳夫斯基（KPS）评分均较治疗前升高,且研究组高于对照组（P<0.05）。两组不良反应发生率对比未见统计学差异（P>0.05）。结论：三维适形调强放疗联合榄香烯注射液治疗食管癌患者,疗效较好,可有效阻止疾病进展,改善患者生存质量和降低血清肿瘤标志物水平,减轻机体免疫抑制,且不增加不良反应发生率。     

急性低氧下去甲肾上腺素对大鼠淋巴细胞转化的调节作用

本研究以模拟高原低氧方法,观察低氧作用于大鼠细胞免疫功能以及去甲肾上腺素对免疫作用的调节机制。实验结果：与对照相比,７ｋｍ急性低氧２４ｈ淋巴细胞转化下降４１％（Ｐ〈０．０１）;５ｋｍ低氧暴露时间为７ｄ,２０ｄ时,低氧抑制淋巴细胞转化,分别下降３４％和６０％（Ｐ〈０．０１）,侧脑室注入５ｎｍｏｌ／Ｌ ＮＥ,淋巴细胞转化比对照下降２９％（Ｐ〈０．０１）,７ｋｍ１０ｈ低氧暴露时,侧脑室注入酚妥拉明２５μ     

A negative resistance region underlies the triggering property of membrane potential in human T-lymphocytes

Steady-state current-voltage relationships (SSCVRs) of the plasma membrane of human T-lymphocytes were studied at the physiological temperature of 37°C by using the whole-cell patch-clamp technique. SSCVRs displayed a characteristic N-like shape with a negative resistance region (NRR) in a voltage range of −45 to −35 mV. The majority of cells assayed revealed SSCVR patterns crossing the V-axis at three points (in mV): V₁ = −55 to −45, V₂ = −40 to −35, V₃ = −30 to −10. SSCVRs of T-cells activated by phytohaemagglutinin (48–96 h) also displayed NRR, but crossed the V-axis at one point only (V₁ = −55 to −60 mV). It implies the possibility of two stable levels of membrane potential (V₁ and V₃) for the resting T-cells, but only one (V₁) for activated T-cells. These data thus account for the triggering property of T-cell membrane potential previously reported. The NRR can be explained on the basis of the Hodgkin-Huxley type n⁴j model of K⁺ channel kinetics. According to the model the possibility for a membrane to have on or two stable levels of membrane potential depends on the ratio of selective K⁺ conductance to non-selective leaky conductance (G_k/G_leak). The steady-state level of K⁺ conductance in resting T-lymphocytes proved to be sensitive to Ca²⁺. Buffering Ca²⁺ ions from either external or internal solution resulted in an appreciable increase in K⁺ conductance. The possibility for membrane potential have two stable levels of membrane potential in connection with the Ca²⁺ dependence of K⁺ conductance was supposed to be important for Ca²⁺-signalling during T-cell activation.     

Pore size of swelling-activated channels for organic osmolytes in Jurkat lymphocytes, probed by differential polymer exclusion

The present study explores the impact of the molecular size on the permeation of low-molecular-weight polyethylene glycols (PEG200-1500) through the plasma membrane of Jurkat cells under iso- and hypotonic conditions. To this end, we analyzed the cell volume responses to PEG-substituted solutions of different osmolalities (100-300 mOsm) using video microscopy. In parallel experiments, the osmotically induced changes in the membrane capacitance and cytosolic conductivity were measured by electrorotation (ROT). Upon moderate swelling in slightly hypotonic solutions (200 mOsm), the lymphocyte membrane remained impermeable to PEG300-1500, which allowed the cells to accomplish regulatory volume decrease (RVD). During RVD, lymphocytes released intracellular electrolytes through the swelling-activated pathways, as proved by a decrease of the cytosolic conductivity measured by electrorotation. RVD also occurred in strongly hypotonic solutions (100 mOsm) of PEG600-1500, whereas 100 mOsm solutions of PEG300-400 inhibited RVD in Jurkat cells. These findings suggest that extensive hypotonic swelling rendered the cell membrane highly permeable to PEG300-400, but not to PEG600-1500. The swelling-activated channels conducting PEG300-400 were inserted into the plasma membrane from cytosolic vesicles via swelling-mediated exocytosis, as suggested by an increase of the whole cell capacitance. Using the hydrodynamic radii R_h of PEGs (determined by viscosimetry), the observed size-selectivity of membrane permeation yielded an estimate of ∼ 0.74 nm for the cut-off radius of the swelling-activated channel for organic osmolytes. Unlike PEG300-1500, the smallest PEG (PEG200, R_h = 0.5 nm) permeated the lymphocyte membrane under isotonic conditions thus leading to a continuous isotonic swelling. The results are of interest for biotechnology and biomedicine, where PEGs are widely used for cryopreservation of cells and tissues.     

Direct application of plasmid DNA containing type I interferon transgenes to vaginal mucosa inhibits HSV-2 mediated mortality

The application of naked DNA containing type I interferon (IFN) transgenes is a promising potential therapeutic approach for controlling chronic viral infections. Herein, we detail the application of this approach that has been extensively used to restrain ocular HSV-1 infection, for antagonizing vaginal HSV-2 infection. We show that application of IFN-α1, -α 5, and -β transgenes to vaginal mouse lumen 24 hours prior to HSV-2 infection reduces HSV-2 mediated mortality by 2.5 to 3-fold. However, other type I IFN transgenes (IFN- α 4, -α 5, -α 6, and -α 9) are non effectual against HSV-2. We further show that the efficacy of IFN-1 transgene treatment is independent of CD4+ T lymphocytes. However, in mice depleted of CD8+ T lymphocytes, the ability of IFN-α 1 transgene treatment to antagonize HSV-2 was lost.     

Integrating genealogical and dynamical modelling to infer escape and reversion rates in HIV epitopes

The rates of escape and reversion in response to selection pressure arising from the host immune system, notably the cytotoxic T-lymphocyte (CTL) response, are key factors determining the evolution of HIV. Existing methods for estimating these parameters from cross-sectional population data using ordinary differential equations (ODEs) ignore information about the genealogy of sampled HIV sequences, which has the potential to cause systematic bias and overestimate certainty. Here, we describe an integrated approach, validated through extensive simulations, which combines genealogical inference and epidemiological modelling, to estimate rates of CTL escape and reversion in HIV epitopes. We show that there is substantial uncertainty about rates of viral escape and reversion from cross-sectional data, which arises from the inherent stochasticity in the evolutionary process. By application to empirical data, we find that point estimates of rates from a previously published ODE model and the integrated approach presented here are often similar, but can also differ several-fold depending on the structure of the genealogy. The model-based approach we apply provides a framework for the statistical analysis and hypothesis testing of escape and reversion in population data and highlights the need for longitudinal and denser cross-sectional sampling to enable accurate estimate of these key parameters.     

Predicting the potential impact of a cytotoxic T-lymphocyte HIV vaccine: how often should you vaccinate and how strong should the vaccine be?

To stimulate the immune system's natural defenses, a post-infection HIV vaccination program to regularly boost cytotoxic T-lymphocytes has been proposed. We develop a mathematical model to describe such a vaccination program, where the strength of the vaccine and the vaccination intervals are constant. We apply the theory of impulsive differential equations to show that the model has an orbitally asymptotically stable periodic orbit, with the property of asymptotic phase. We show that, on this orbit, the vaccination frequency can be chosen so that the average number of infected CD4(+) T cells can be made arbitrarily low. We illustrate the results with numerical simulations and show that the model is robust with respect to both the parameter choices and the formulation of the model as a system of impulsive differential equations.